- Spectral and physicochemical characterization of dysprosium-based multifunctional ionic liquid crystals
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We report on the synthesis and characterization of multifunctional ionic liquid crystals (melting points below 100 °C) which possess chirality and fluorescent behavior as well as mesomorphic and magnetic properties. In this regard, (1R,2S)-(-)-N-methylephedrine ((-)MeEph), containing a chiral center, is linked with variable alkyl chain lengths (e.g., 14, 16, and 18 carbons) to yield liquid crystalline properties in the cations of these compounds. A complex counteranion consisting of trivalent dysprosium (Dy3+) and thiocyanate ligand (SCN-) is employed, where Dy3+ provides fluorescent and magnetic properties. Examination of differential scanning calorimetry (DSC) and hot-stage polarizing optical microscopy (POM) data confirmed liquid crystalline characteristics in these materials. We further report on phase transitions from solid to liquid crystal states, followed by isotropic liquid states with increasing temperature. These compounds exhibited two characteristic emission peaks in acetonitrile solution and the solid state when excited at ex = 366 nm, which are attributed to transitions from 4F9/2 to 6H15/2 and 4F9/2 to 6H13/2. The emission intensities of these compounds were found to be very sensitive to the phase.
- Lu, Chengfei,Das, Susmita,Siraj, Noureen,Magut, Paul K. S.,Li, Min,Warner, Isiah M.
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p. 4780 - 4786
(2015/06/02)
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- Deracemization of bilirubin as the marker of the chirality of micellar aggregates
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The deracemization of bilirubin in micellar aggregates of structurally correlated chiral surfactants was studied by circular dichroism experiments and exploited as the marker of the expression of chirality of the aggregates. The obtained results suggest that the hydrophobic interactions control the transfer of chirality from the monomers to the aggregates, and that different regions of the same aggregate might feature opposite enantiorecognition capabilities.
- Sorrenti, Alessandro,Altieri, Barbara,Ceccacci, Francesca,Di Profio, Pietro,Germani, Raimondo,Giansanti, Luisa,Savelli, Gianfranco,Mancini, Giovanna
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experimental part
p. 78 - 85
(2012/03/26)
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- Solvent-free microwave-assisted preparation of chiral ionic liquids from (-)-N-methylephedrine
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An efficient method for the preparation of chiral ionic liquids based on (1R,2S)-(-)-ephedrinium salts under solvent-free conditions and microwave activation is described. The influence of non-specifically thermal microwave effects - consistent with mecha
- Thanh, Giang Vo,Pegot, Bruce,Loupy, Andre
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p. 1112 - 1116
(2007/10/03)
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- FUNCTIONAL MICELLAR CATALYSIS. PART 7. CLEAVAGE OF ACTIVATED ENANTIOMERIC SUBSTRATES BY CHIRAL FUNCTIONAL SURFACTANT SYSTEMS
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The cleavage of enantiomeric p-nitrophenyl derivatives of the N-methyl-N-1--ethylcarbamate (3), the 1-methylheptyl carbonate (4) and the α-methoxyphenylacetate (5) in the presence of homomicelles of N-hexadecyl-N-methylephedrinium b
- Fornasier, Roberto,Tonellato, Umberto
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p. 1313 - 1316
(2007/10/02)
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- SYNTHESES D'OXYDES DE PHOSPHINES OPTIQUEMENT ACTIFS PAR LA TECHNIQUE DU TRANSFERT DE PHASE
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Asymmetric induction in phosphine oxides 5-8 synthesized from prochiral phosphonium compounds 1-4 is reported.When 1-4 react under PTC conditions using an optically active quaternary ammonium salt as a chiral catalyst, phosphine oxides 5-8 are obtained wi
- Bourson, J.,Goguillon, T.,Juge, S.
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p. 347 - 356
(2007/10/02)
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